Fuel injector-igniter



Oct. 16, 1962 c. H. MAY

FUEL INJECTOR-IGNITER Oct, 16, 1962 c. H. MAY 3,058,453

FUEL INJECTOR-IGNITER Filed Feb. l5, 1960 3 Sheets-Sheeil 2 'n am fgagf@r mum/g rae This invention relates generally to internal combustionengines and more particularly to a novel fuel injectorigniter for aninternal combustion engine.

This application is a continuation-in-part of my copending applicationSerial No. 8,784, filed February l5, 1960, entitled Fuellnjector-Igniter.

As explained in greater detail in my aforementioned copendingapplication, a pronounced improvement in internal combustion systems maybe obtained by effecting ignition of the fuel used to supply energy tothe system immediately prior to introduction thereof into a combustionchamber or working cylinder. The present invention provides a structurefor accomplishing such ignition of the fuel in a manner somewhatdifferent from that disclosed in my copending application. f

Accordingly, the broad object of the present invention is an improvedcombustion system for an internal combustion engine.

Another object is a combustion system that provides for the concurrentejection and ignition of fuel.

Another object is a combustion system wherein ignition occurs at theonset of fuel injection and is of a continuous nature thereafterprecluding ignition lag or delay of ignition within the expansionchamber.

Another object is a fuel injector-igniter having selfcontained fuelmetering means.

Another object is a fuel injector-igniter having a selfcontained fuelmetering means controllable solely by fuel pressure.

Other objects and advantages of the present invention will becomeapparent from the following detailed description wherein reference ismade to the drawings, in which:

-FIGURE l is a sectional side elevational view of a fuelinjector-igniter in accordance with one embodiment of the presentinvention;

F.lG. 2 is a sectional side elevational View taken along the line 2-2 ofFIG. l;

FIG. 3 is a fragmentary sectional view of the fuel injector-igniter ofFIG. l, enlarged for clarity;

FIG. 4 is a fragmentary sectional view of the nozzle portion of the fuelinjector-igniter of FIG. 1, enlarged for clarity; and

FIG. 5 is a sectional view of a modified form of a fuel metering systemusable with the fuel injector-igniter of the present invention.

A fuel injector-igniter 10, in accordance with an exemplary embodimentof the present invention, comprises a tubular housing or cylinder 12,having a lower end 14 with a threaded portion 16 thereon for engagementwith a suitably threaded portion 17 of a nozzle retainer 18. The nozzleretainer 18 has a transversely extending end or cap portion 20 and adownwardly extending neck portion 22 having a central bore 23 therein.The neck portion 22 of the nozzle retainer 18 has a threaded portion 24so as to be engageable in a suitably threaded aperture, for example thespark plug aperture 26 of a cylinder head 27 of a conventional internalcombustion engine (not shown). A suitable sealing washer 28 is disposedin a peripheral recess 29 in the nozzel retainer 18 to eifect a uid sealbetween the nozzle retainer 18 and the cylinder head 27.

A nozzle 30, having a longitudinally extending upper end portion 31 ofsubstantially the same diameter as Patented oct. 1e, 1962 the insidediameter of the cylinder 12 so as to be closely engagable therewith, issupported between the nozzle retainer 18 and the cylinder 12. The upperend portion 31 of the nozzle 30 has a downwardly convergent inner face32 that terminates in a downwardly convergent conical pintle seat 34(FIG. 4). The pintle seat 34 communicates with a vertically extendingorice 36 that communicates with a downwardly divergent nozzle 38 in adownwardly extending tubular extension 40 of the nozzle 30. Theextension 40 is accepted in the bore 2.3 of the nozzle retainer 18. Thedownwardly convergent conical pintle seat 34, in conjunction with theorifice 36 and downwardly divergent nozzle 3S `define venturi for thepassage of burning fuel, as will be described hereinafter.

A counterbore 41 is provided at the upper end of the bore 23 adjacent anupper end face 42 of the nozzle retainer 18 for the acceptance of asuitable sealing washer '43 that, in conjunction with a similar washer44 disposed between an annular lower end face 45 on the cylinder 12 anda peripheral flange 46 on the nozzle 30, functions to seal the nozzle 30with respect to the cylinder 12 and nozzle retainer 18 against thepassage of fluids.

A plunger 60 is disposed for reciprocal movement withing the cylinder 12for the compression of air in a compression chamber 62 deued by adownwardly convergent conical bottom face 64 on the plunger 60 incombination with the downwardly convergent conical upper end face 32 ofthe nozzle 30 and an inner wall 66 of the cylinder 12. The diameter ofthe plunger 60 is substantially the same as the diameter of the innerwall 66 of the cylinder 12 to effect a lluid sealing fit therebetween.Air is admitted into the chamber 62 through a plurality of apertures 68spaced radially around the cylinder 12 that are uncovered by the plunger60 when the plunger 60 is in its uppermost position ('FIG. 2). Downwardmovement of the plunger 60 within the cylinder 12 closes off theapertures 68 thereafter compressing air within the chamber 62.

The plunger 60 is of generally U-shaped vertical crosssectionalconfiguration having a bight portion 70 and a pair of upstanding legportions 72 and 74. The leg portions 72 and 74 are retained radiallywith respect to one another by a plunger cap 76 having a centralaperture 77 extending therethrough for a reason to be discussed. The legportions 72 and 74 of the plunger 60 are of arcuate horizontalcross-section so as to be slidably acceptable within the cylinder 12.The leg portions 72 and 74 have thickened upper end portions 78 and 80,respectively, with downwardly extending ribs 82 and 84 thereon forlocking engagement with a pair of complementary upwardly extending-arcuate ribs 86 and 88 on a pair of spring spacers 90 and 92,respectively. The spring spacers 90 and 92 are of arcuate horizontalcross-section so as to be slidable longitudinally of the cylinder 12 inclosely spaced relationship to the outer peripheral surface thereof. Thecylinder 12 is therefore acceptable between the concentric leg portions72 and 74 of the plunger '60 and the spring spacers 90 and 92,respectively.

The plunger 60 is normally biased upwardly with respect to the housingor cylinder 12 by an operating spring that extends between an annularlower end face 102 on a spring retainer 104 and an upper end' face 105on the nozzle retainer 18. The spring retainer 104 has a circular groove106 therein for the acceptance of complementary ribs 108 and 110 on thespring spacers 90 and `92, respectively. Therefore, the upward bias ofthe operating spring 100 locks the spring retainer 104, and the springspacers 90 and 92 to the upper end portions 73 and 80 of the plunger 60.

Referring to FIGURE 2, the cylinder 12 has a radially outwardlyextending flange portion 122 that delines a. transversely extendingannular seat 124 for the seating of a pump holder 126. The pump holder126 has a lower end face 128 that is engageable with the seat 124 tolimit downward movement of the pump holder 126 with respect to thecylinder 12. The pump holder 126 is biased against the seat 124 on theflange 122 by a radially 1nwardly extending ange 129 on a locking ring130 having a central aperture 131. The locking ring 130 is threadablyengageable with a suitably threaded portion 132 on the upper end portion134 of the cylinder 12. rThe upper end portion 134 of the cylinder 12 isspaced radially outwardly from the cylinder 12 and from an intermediatecylindrical portion 135 by a transverse flange 136 that extends radiallyoutwardly between the upper end portion 134 and the tubularlongitudinally extending portion 135.

Referring to FIGURE 3, a pump housing 160, having an upwardly extendingtubular wall portion 162 and a transverse lower end wall 164 is disposedcentrally of the plunger 60 and pump holder 126. The side wall 162 ofthe pump housing 160 has a threaded portion 16S thereon for threadedengagement in a suitably threaded bore 166 in the pump holder 126. It isto be noted that because the pump holder 126 is seated against the endface 124 on the cylinder 12, rotation of the pump housing 160 withrespect to the pump holder 126 effects an axial movement of the pumphousing 160 with respect to the cylinder 12. This axial adjustment ofthe pump housing 160 with respect to the cylinder 12 effects a rstadjustment of the metering of the fuel injector as will be describedhereinafter.

A valve body 180 is sldably disposed within a central bore 182 in thepump housing 160 in close fitting relationship. A uid seal is effectedbetween the valve body 180 and the central bore 182 of the pump housing160 by a pair of O-rings 184 and 186 that are disposed in suitablecircumferentially extending annular recesses 188` and 190 on theperiphery of the valve body 180.

The valve body 180 has a central bore 192 therein that functions as avalve chamber 194. A bore 196 communicates with the valve chamber 194and' with the upper end of the valve body 180. A check valve 198 isnormally seated against a conical valve seat 200 that extends betweenthe bore 192 and bore 196 in the valve body 180. The check valve 198 isbiased against the seat 200 by a helical compression spring 202 thatextends 'between the check valve 198 and an upper end face 201 of ametering screw 204. The metering screw 204 is threadably engaged in athreaded counterbore 206 in the valve body 180. A sealing washer 210 isbiased against a transversely extending annular washer Aseat 212 at theupper end of the counterbore 206 by an upper end face 201 on themetering screw 204.

The metering screw 204 has a central `bore 214 that communicates with abore 216 at the upper end of the metering screw 204 and with the valvechamber 194. The bore 216 functions as a fuel metering orifice betweenthe chamber 194 and the Ibore 214, for a reason to be discussedhereinafter. A washer 220 is seated between the metering screw 204 andthe end face 222 of the bore 182 to retain an O-rng 224.

'The pump housing 160 is closed, at the upper end portion 162 thereof,by an adapter 230 having a threaded central bore 232 therein for theacceptance of a conventional conduit locking screw 234. The lockingscrew 234 has a central bore 236 for the acceptance of a suitable fuelconduit 238 that is securely held within the adapter 230 by the lockingscrew 234. The adapter 230 has an annular recess 239 therein for theacceptance of a suitable sealng member 240, for example a conventionalCaring. The sealing member 240 effects a fluid seal between the adapter230 and the tubular side walls 162 of the pump housing 160.

The locking screw 234, adapter 230, pump body 180 and washer 220 arebiased downwardly in the pump housing 160 -by a retainer plug 241 havingan externally threaded portion 242 that is threadably engageable in thethreaded lbore 166 in the pump holder 126. The retainer plug 241 has apair of spaced parallel ats 244 and' 246 thereon to facilitate downwardrotation thereof with respect to the pump holder 126, as by aconventional wrench, thereby to lock the aforementioned componentsagainst axial movement with respect to the pump housing and the pumpwith respect to the pump holder 126.

An upper end portion 250 of a tubular pintle shaft 252 extends into thebore 214 of the metering screw 204. A sliding seal is effected between'the pintle shaft 252 and the pump housing 160 by the sealing ring 224.A central passage 255 in the pintle shaft 252 provides lfor the passageof fuel downwardly through the pintle shaft 252 from the bore 214 in themetering screw 204 as will be discussed. The pintle shaft 252 has athreaded lower end portion 256 that is engageable in a complementaryinternally threaded portion 257 in a tubular pintle body 260.

The pintle body 260 extends downwardly through a central bore 264 in thebight portion 70 of the plunger 60 in slidable engagement therewith. Thepintle body 260 extends downwardly through the compression chamber 62for the support of a pintle tip 270 that is threadably engaged with aninternally threaded end portion 272 of the pintle 'body 260. The pintletip 270 has a radially outwardly extending annular ange 274 thereon thatis engageable with an annular lower end face 276 of the pintle -body 260to position the pintle tip 270 axially with respect to the pintle body260. A lower end face 278 of the annular flange 274 is of truncateddownwardly convergent conical configuration of a predetermined area, fora reason to be discussed. The pintle tip 270 has a downwardly convergentconical end face 280 complementary to the conical seat 34 in the nozzle30 so as to be engageable therewith in lluid sealing engagement. Aspacer tube 290 extends centrally and longitudinally within the pintlebody 260 and has a central passageway 292 therein to facilitate thepassage of fuel downwardly from the central passageway 255 in the pintleshaft 252 into a cavity or fuel pre-chamber 294 within the pintle tip270.

The pintle lbody 260 and therefore the end face 280 of the pintle tip270 are biased Adownwardly with respect to the cylinder 12 and into theseat 34 in the nozzle 30 by a plurality of disk or Belleville washers300 of truncated conical cross-sectional conguration that are stacked-with the radially inwardly convergent portions thereof in juxtaposedrelation. The washers 300 extend between la lower end face 302 on theend wall 164 of the pump housing 160 and a transverse annular end face306 on the pintle body 260 thereby biasing the end face 280 of thepintle tip 270 against its complementary seat 34 in the nozzle 30.

The pintle tip 270 has a plurality of downwardly divergent passageways310 that communicate with the chamber 294 therein for the passage offuel outwardly of the chamber 294 as will Abe discussed. The pintle body260 has a transverse Ibore 312 that communicates with a transverse bore314 in the pintle tip 270. The bore 314 communicates with a central bore316 in the pintle tip 270. A longitudinally extending groove 320 on theouter periphery of the pintle body 260 communicates with the transversebore 312 in the pintle body 260, and therefore the bore 314 in thepintle tip 270, at such times as a circumferential recess 322, that isspaced axially upwardly within the bore 264 of the plunger 60, isaligned with Ithe bore 312. The recess 322 is so positioned in the bore264 that it provides communication between the transverse apertures 312and 314 in the pintle body 260 and pintle tip 270, respectively, Aandthe longitudinal groove 320 when the plunger 60 is in its lowermostposition with respect to the cylinder i12.

Upon actuation of the fuel injector-igniter 10 of the present invention,as by moving the plunger 60 downwardly within the cylinder 12 by asuitable mechanism (not shown), a fresh charge of air within thecompression chamber 62 is compressed therein upon passage of the plunger60 past the inlet apertures 68 in the cylinder 12. As the plunger 60moves downwardly with respect to the cylinder 12 air pressure within thecompression chamber 62 builds up until, as the plunger 60 approaches thelower end of the cylinder 12, air pressure acting upon the annularsurface 27S on the pintle tip 270 is sufficient to bias the pintle tip270 and pintle body 260 upwardly against the bias of the stackedBelleville washers 300. At this time the compressed and heated airwithin the now relatively small compression chamber 62 passes downwardlypast the radially outwardly extending passageway 310 in the pintle tipdrawing fuel outwardly of the fuel pre-chamber 294 therein and into theventuri defined by the radially downwardly convergent seat 34,passageway 36 and radially downwardly divergent nozzle 38. Simultaneously, the fuel charge disposed in the fuel pre-Chamfber 294 of thepintle tip 270 is subjected to an increased pressure by air passinginwardly of the pintle tip 270 through the longitudinal passageway 320,annular recess 322, and the apertures 312 and 314 in the pintle body 260and pintle tip 270, respectively. It will be noted that at this time apressure differential exists between the fuel pre-chamber 294 and theorifice 36 which pressure differential operates to force the fueloutwardly at a high velocity.

Because air within the compression chamber 62 is compressed well above1000 p.s.i. and thereby to raise its temperature well above the ignitionpoint of the fuel charge contained within the chamber 294, the fuel isignited upon passage thereof outwardly of the downwardly divergentpassageways 310 and within the orifice 36 of the nozzle 30. Therelatively lower pressure within the orifice 36 draws Vthe fluiddownwardly and outwardly of the chamber 294 where it is atomized andignited by the compressed air passing between the conical surface 280 onthe pintle tip 270 and the conical seat 34 on the nozzle 30.

Upward movement of the plunger 60 under the bias of the operating spring100, upon release of 'the downward bias thereon by a cam or othersuitable mechanism (not shown), effects a partial vacuum within thecompression chamber 62 which extends into the valve chamber 194. Becausea constant fuel pressure is maintained within the conduit 238, as by afuel pump (not shown), the fuel inlet valve 198 is biased downwardlyagainst the spring 202` when a predetermined pressure differential onopposite sides of the valve 198 is reached. The fuel flows downwardlythrough the fuel inlet chamber 194 due `to the aforementioned pressuredifferential and through the aperture 216 in the metering plug 204.Because the aperture 216 functions as an orifice the flow of fuelbetween the chamber 194 and the bore 214 is throttled, the amount offuel passing the orifice 216 being dependent upon the time required forthe plunger to move from its lowermost position after injection ofignited fuel through the nozzle 30 to the point where the apertures 68in the cylinder 12 are open thereby breaking the partial vacuum withinthe compression chamber 62 and reducing the pressure differential onopposite sides of the fuel inlet valve 198 to permit Closure of thevalve 19S. Therefore, the amount of fuel injected upon each stroke ofthe plunger 60 is determined by the fuel pressure in the line 23S asrelated to the size of the orifice `216 and the speed of return of theplunger 60 from the injection position to the venting of the compressionchamber upon opening of the apertures 68.

A modified fuel metering system is shown in FIGURE disposed within thepump housing 160 discussed hereinbefore. The upper end portion 250 ofthe pintle shaft 252 is associated with the pump housing 160 and sealingwasher 253 in the manner discussed hereinbefore. A pump body 402 isdisposed within the interior bore 182 of the pump housing 160. The pumpbody 402 has an upper annular recess 404 for the acceptance of an uppersealing washer 406, for example, an O-ring, to effect a uid seal betweenthe pump body 402 and pump housin 160.

gl`he pump body 402 has a longitudinally extending bore 410 that isoffset from the central longitudinal axis of pump body 402 andcommunicates with -a longitudinally extending bore 412 that defines ashuttle chamber 414. The bore 412 communicates with the bore 414ithrough a passageway 416 at the upper end of the bore 412. Afrusto-conical valve seat 418 extends between the bores 412 and 416 forthe seating of a shuttle 420. The shuttle 420 has a frusto-conical upperend portion 422 complementary to the valve seat 418 to effect a fluidsealing seat therebetween.

A lower end plug 430 for the pump body 402 is disposed in a recess 432in the lower end of the pump body 402. The end plug 430 has an upper endportion 434 that extends into an offset bore 436 in the recess 432 ofthe pump body 402. The upper end portion 434 of the end plug 430 has acentral passageway 438 therein that communicates with the bore 412 andtherefore the shuttle chamber 414 in the pump body 402. The upper endportion 434 of the end plug 430 has a frusto-conical valve seat 440complementary to a frusto-conical seating surface 442 on the shuttle 420so as to effect a fluid sealing seat between the shuttle 420 and the endplug 430 when the shuttle 420 is in its lowermost position.

A passageway 450 extends radially outwardly from a central bore 452 inthe end plug 430` for communication with the passageway 43S in the upperend portion 434 of the end plug 430. The upper end portion 250 of thepintle shaft 252 is slidably disposed in the central bore 452 of the endplug 430. A suitable sealer washer 453 effects a fluid seal between theend plug 430 and the housing 160.

The pump body 402 has a threaded transverse bore 460 for the acceptanceof a suitably threaded diaphragm retainer 462. The diaphragm retainerscrew 462 has `a central bore 464 for the acceptancel of a meteringpiston 466 that is slidable therein transversely of the pump body 402. Ametering valve spring 468 normally biases the piston 466 to an indexposition defined by an end wall 470 of the bore 460. A diaphragm 472,preferably of, for example, silicone rubber, extends across the end wall470 of the bore 460 and is held, at its outer periphery, against adiaphragm seat 474 by an end face 476 on the diaphragm retainer screw462. A bore 480 communicates with the shuttle chamber 414 and with thediaphragrn 472 thereby to define a fuel metering chamber 481.

An adaptor 486 closes the pump housing 160 and has an annular recess 488therein for the acceptance of a seal 490, for example an O-ring, toeffect `a fiuid seal between the adaptor 486 and the pump housing 160.The end plug 486 has a threaded central bore 489 for the acceptance of aconventional conduit locking screw 490i that has a central bore 492therein for the acceptance of a uid conduit 494. The locking screw 490holds the conduit 494 in fluid sealing relationship with respect to theupper end plug 486 in the conventional manner. A lower end portion 496of the conduit 494 extends into a chamfered counterbore 498 in theadaptor 486 thereby to be in fluid communicating relationship with thelongitudinal bore 410 in the pump body 402.

-Upward movement of the plunger 60 under the bias of the operatingspring reduces the pressure in the compression chamber 62. This loweredpressure extends through the apertures 312 and 314 in the pintle body260 and pintle tip 27 0, respectively, and upwardly through the centralpassage 255 in the pintle shaft 252, permitting the piston 466 to biasthe diaphragm 472 to the left to push fuel outwardly of the meteringchamber 481 and downwardly into the fuel pre-chamber 294 in the pintletip 270, the metering chamber 481 having been filled and the pistonbiased to the retracted position on the compression stroke of theplunger 60, as will be described. At such time as the pressuredifferential on opposite sides of the shuttle increases suliciently toeffect downward movement of the shuttle 420 due to fuel pressure in theconduit 494, the flow of fuel outwardly of the metering chamber isterminated. Fuel then flows into the metering chamber-481 and the piston466 is moved to the right, as seen in the drawings, an amount relateddirectly to the upstream pressure of the fuel. Therefore, the volume ofthe chamber 481 and, accordingly, the quantity of fuel contained thereinis directly related to the upstream pressure of the fuel.

As the plunger 160 commences a downward stroke under the influence ofsuitable mechanism (not shown) increased pressure in the compressionchamber 62, acting through the passages 312, 314 and 255, biases theshuttle 420 upwardly against the seat 418 in the valve body 402. Theincreased pressure then biases the piston 466 to the right completelycompressing the spring 468 and thereby preparing the piston 466 for thenext fuel ejection stroke upon release of the pressure. Upon release ofthe pressure effective on the piston 466, fuel within the meteringchamber 481 is pumped downwardly through the passages 438, 456 and 255into the fuel pre-chamber 294 in the pintle head 270, as discussedhereinbefore. Therefore, on each complete cycle of the plunger 160 a newcharge of fuel is first metered in the metering chamber 481 and thendeposited in the fuel pre-chamber 2.94, the quantity thereof beingdirectly related to fuel pressure in the conduit 494. This novel valvingstructure permits positive control of the energy input of the fuelinjectorigniter to an internal combustion engine by simply controllingHuid pressure at a point upstream from the injector-igniter 10.

It is to be noted that the combustion system of the present inventioneffects supercompression of air only as opposed to the compression of anair-fuel mixture heretofore known in the art. Further thesupercompressed air is employed to pick up the fuel charge and carry itinto the combustion chamber. The use of a convergentdivergent venturiaids in drawing the fuel into proximity with the supercompressed air andin admixing the charges due to relatively high turbulence within thehigh velocitylow pressure are-a of the venturi. A means is providedthat, in combination with the venturi, effects a pressure differentialon opposite sides of the fuel charge.

Further, the use of a reciprocable pintle as a differential area valveresults in the injection of the entire portion of supercompressed airand fuel into the working cylinder, precluding entrapment thereof.

Another feature of the present invention is the angular relationshipbetween the supercompressed air passages and the fuel passages thatresults in relatively eicient admixing of the air and fuel.

From the foregoing description, it is apparent that the combustionsystem of the present invention, which provides for the simultaneousinjection and ignition of a fuel into a combustion chamber of aninternal combustion engine, reduces the deleterious effects of ignitionlag and offers material advantages in terms of combustion, expansion,and thermal efficiencies. The problems heretofore attendant with theignition of relatively lean mixtures and operation at low loadconditions are substantially eliminated.

While it will be apparent that the embodiments of the invention hereindisclosed are well calculated to fulfill the objects of the invention,it will be appreciated that the invention is susceptible tomodification, variation and change without departing from the properscope or fair meaning of the subjoined claims.

What Vis claimed is:

1. A fuel injector-igniter for an internal combustion engine having anexpansion chamber, said injector-gniter comprising a supercompressionchamber, means for supporting a liquid fuel charge internally of saidsupercompression chamber, means reciprocable within saidsupercompression chamber for compressing a relatively small volume ofair in isolated relationship with respect to the expansion chamber to apredetermined pressure having a temperature sufficient to ignite saidfuel, and means for admixing said supercompressed air and said fuel toignite and inject said fuel into the expansion chamber upon theoccurrence of said predetermined fluid pressure comprising a venturinormally closed by said fuel supporting means and openable on theoccurrance of said predetermined pressure in said supercompressionchamber, and a plurality of radially spaced passage means in said fuelsupporting means communicating with the convergent section of saidventuri and with said fuel charge whereby upon opening of said venturithe liow of fuel from said passage means, respectively, converges at theconstricted portion of said venturi to effect maximum impact atomizationand ignition of said fuel.

2. A fuel injector-igniter for an internal combustion engine having anexpansion chamber comprising means for metering a charge of fuelincluding a metering charnber having a fuel inlet and a fuel outlet, ashuttle valve within said metering chamber and operable to close saidinlet or outlet aperture, selectively, and means for operating theshuttle valve in response to av predetermined pressure condition tocontrol fuel ow, means for isolating said fuel charge from the expansionchamber, a supercompression chamber, means for compressing a fluid insaid supercompression chamber in isolated relationship with respect tothe expansion chamber to a pressure having a temperature sutiicient toignite said fuel, means for admixing said fluid and said fuel thereby toignite said fuel, and means for injecting said liuid and ignited fuelmixture into the expansion chamber.

3. An injector-igniter in accordance with claim 2 wherein the meteringchamber has a variable volume.

4. A fuel injector-igniter for an internal combustion engine having anexpansion chamber, said injector-igniter comprising a cylinder, aplunger reciprocable within said cylinder for compressing a fluid, meanswithin said plunger for metering a charge of fuel, means for isolatingsaid fuel charge from the expansion chamber, means on said plunger forconducting a charge of fuel between said metering means and saidisolating means, means responsive to a predetermined pressure foradmixing said fluid and said fuel thereby to ignite said fuel, and meansfor injecting said uid and ignited fuel mixture into the expansionchamber.

References Cited inthe file of this patent UNITED STATES PATENTS1,329,797 Raabe Feb. 3, 1920 1,501,884 Short et al. July 15, 19241,896,174 Honn Feb. 7, 1933 2,033,155 Scott Mar. 10, 1936 2,091,987 HonnSept. 7, 1937 FOREIGN PATENTS 469,107 France May ll, 1914

